DAPRA’s DiscRotor Concept

Boeing is building a 20%-scale telescoping-blade disc-rotor model for windtunnel-testing next summer under DARPA’s DiscRotor program to demonstrate technology for a high-speed VTOL combat search-and-rescue aircraft. Invented by Danish engineer Jacob Ellehammer early last century, the disc-rotor has a disc with blades attached that acts as a helicopter rotor in vertical flight and a wing in forward flight.